Methods of forming cyclopirox or derivatives thereof in a subject by administration of prodrug

ABSTRACT

A method of forming a compound in a subject can include: providing a composition having a prodrug compound represented by a structure of Formula 1 or stereoisomer thereof or pharmaceutically acceptable salt thereof; and administering the composition to a subject such that the prodrug compound has a phosphoryloxyalkyl prodrug moiety removed therefrom to form the compound in the subject and to form the separate phosphoryloxyalkyl compound. The prodrug can be included in a pharmaceutical composition for use in treatment of fungus, various cancers (e.g., bladder, breast, etc.), dermatitis, superficial mycoses; inflammation, tinea pedis, tinea cruris, and tinea corporis,  Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum , and  Microsporum canis , candidiasis (moniliasis),  Candida albicans , tinea (pityriasis) vesicolor,  Malassezia furfur , acute myeloid leukemia, acute lymphoid leukemia, chronic myelogenous leukemia, lymphoma or multiple myeloma.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 14/059,287 filed Oct. 21, 2013, which is adivisional of U.S. patent application Ser. No. 13/310,087 filed Dec. 2,2011 now U.S. Pat. No. 8,609,637, which claims benefit of U.S.Provisional Patent Application 61/419,218 filed on Dec. 2, 2010, andwhich applications are incorporated herein by specific reference intheir entirety.

BACKGROUND

The molecule 6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one, alsoknown as Ciclopirox, is a commercially available antifungal agent as anolamine salt. Ciclopirox olamine has been used to treat superficialmycoses and Tinea versicolor following topical application to the skin.Following enteral administration, ciclopirox undergoes significantfirst-pass effect resulting in low oral bioavailability. The oral routeof administration is also associated with gastrointestinal toxicitiesobserved in animals and humans limiting its benefit in animal and humanhealth applications. Ciclopirox olamine has poor solubility, limitingopportunities to deliver the antifungal agent via parenteraladministration of suitably potent solutions and suspensions. As such, itwould be beneficial to configure ciclopirox for improved watersolubility in order to deliver the drug by parenteral routes ofadministration.

BRIEF DESCRIPTION OF THE FIGURES

The foregoing and following information as well as other features ofthis disclosure will become more fully apparent from the followingdescription and appended claims, taken in conjunction with theaccompanying drawings. Understanding that these drawings depict onlyseveral embodiments in accordance with the disclosure and are,therefore, not to be considered limiting of its scope, the disclosurewill be described with additional specificity and detail through use ofthe accompanying drawings, in which:

FIG. 1 illustrates a schematic representation of a method of preparing6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one, which is referred toherein as Cyclopirox (Scheme 1).

FIG. 2 illustrates a schematic representation of a method of preparingdi-tert-butyl(chloromethyl)phosphate (Scheme 2).

FIG. 3 illustrates a schematic representation of a method of preparing aprodrug of 6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one (Scheme 3).

FIG. 3A illustrates a schematic representation of a sub-reaction processidentified as Scheme 3A, which can be a sub-process of Scheme 3 of FIG.3.

FIG. 3B illustrates a mass spectroscopy chromatograph that shows thereaction products of Scheme 3A of FIG. 3A.

FIG. 3C illustrates a mass spectrometry chromatograph that shows thepresence of the free acid form of((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphate.

FIG. 3D illustrates a dimer-type form of ciclopirox-POM prodrug.

FIG. 3E illustrates a mass spectrometry chromatograph of the dimer-typeform of Ciclopirox-POM prodrug of FIG. 3D.

FIG. 4 illustrates a schematic representation of salting((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphateto obtain ((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphatedisodium salt (Scheme 4).

FIG. 4A illustrates a mass spectrometry chromatograph that shows thepresence of the ((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methylphosphate disodium salt of FIG. 4.

FIG. 5 illustrates a schematic representation of a method of preparingdibenzyl(chloromethyl)phosphate (Scheme 5).

FIG. 6 illustrates a schematic representation of a method of preparingdibenzyl (((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl)phosphate (Scheme 6).

FIG. 7 illustrates a schematic representation of a method of preparing((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate di sodiumsalt (Scheme 7).

FIG. 8 illustrates a schematic representation of a method of preparingthe POM reagent dibenzyl(chloromethyl)phosphate (Scheme 8).

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented herein. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe figures, can be arranged, substituted, combined, separated, anddesigned in a wide variety of different configurations, all of which areexplicitly contemplated herein.

Generally, the present invention relates to prodrugs of6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one, also known asciclopirox. The ciclopirox prodrugs can include a phosphoryloxymethyl(POM) moiety or other phosphoryloxyalkyl (POA) moiety in order toprovide improve solubility and bioavailability to ciclopirox. While thedescription herein describes ciclopirox-POM and the POM prodrug moietyin detail, the prodrug may be ciclopirox-POA and the prodrug moiety isPOA. However, when the prodrug is described as ciclopirox-POM and theprodrug moiety as POM it should be understood that the methyl of POM maybe an alkyl, substituted or unsubstituted so as to be ciclopirox-POA andPOA. As such, POA is a genus that includes the POM species. Discussionsof POM herein as an example refer to POA, and discussions of POA referto the species POM.

The ciclopirox-POM of the present invention can also include derivativesof ciclopirox that include the POM prodrug moiety, which derivativeprodrugs can be referred to herein generally under the termciclopirox-POM or may be specifically referenced as ciclopirox-POMderivatives. The ciclopirox-POM prodrugs of the present invention can beprepared with traditional chemistry techniques, such as those describedherein.

The ciclopirox-POM prodrug has been shown to improve the aqueoussolubility of ciclopirox, and thereby can improve its bioavailabilityvia a number of routes of administration. Accordingly, theciclopirox-POM prodrug overcomes limitations with the formulation and/ordelivery route of ciclopirox or other forms of ciclopirox, such as aciclopirox salt like ciclopirox olamine. The improved solubility of theciclopirox-POM prodrug can now allow for improved pharmaceuticalcompositions for administering effective amounts of ciclopirox. Thepharmaceutical compositions can be formulated to be suitable for theroute of administration, such as intravenous, subcutaneous, oral, ortopical.

The ciclopirox-POM prodrug is configured so that the POM moiety iscleaved off by phosphatase enzymes in order to produce the originalparent drug ciclopirox that is biologically active. As such, theciclopirox-POM can be administered to a living subject, and then beenzymatically processed into bioactive ciclopirox within the body of thesubject. While the subject usually will be human, the ciclopirox-POMprodrugs may be found to be suitable for a wide variety of animals, suchas mammals, birds, reptiles, or the like.

While ciclopirox has traditionally been used as a topical antifungal,the different formulations available for the ciclopirox-POM prodrugs ofthe present invention may provide therapeutically effective amounts ofciclopirox for other maladies that have been shown or that may bedeveloped to be suitable for ciclopirox treatment. Accordingly, theciclopirox-POM prodrugs may be used in therapies for: inhibition,treatment, and/or prevention of a fungus; inhibition, treatment, and/orprevention of various types of cancer (e.g., bladder, breast and othersdescribed herein); inhibition, treatment, and/or prevention ofdermatitis; inhibition, treatment, and/or prevention of superficialmycoses; for inhibition, treatment, and/or prevention of inflammation(e.g., as an anti-inflammatory, or NSAID); and inhibition, treatment,and/or prevention of one or more of tinea pedis, tinea cruris, and tineacorporis, Trichophyton rubrum, Trichophyton mentagrophytes,Epidermophyton floccosum, and Microsporum canis, candidiasis(moniliasis), Candida albicans, tinea (pityriasis) vesicolor, orMalassezia furfur. It has also been found that that ciclopiroxselectively eliminates viral infection by HIV-1, which can be deliveredas ciclopirox-POA prodrug (ciclopirox-phosphoryloxyalkyl prodrug).

The ciclopirox-POM prodrug improves bioavailability of ciclopirox suchthat increased amounts and distributions of the prodrug can be effectiveon cellular and subcellular levels. That is, more ciclopirox can beavailable throughout a subject as well as within individual cells of asubject. The increased amount of available ciclopirox improves thebioactivity and therapeutic potential, as well as improves the abilityto modulate cellular processes. Accordingly, the ciclopirox-POM can beused for disrupting DNA repair, cell division, or intranuclear transportin a cell. The cells may be in vivo, ex vivo, or in vitro.

While prodrugs of ciclopirox have been described, such prodrugs havebeen limited to conventional esters formed with available hydroxyland/or amino groups, such as by acylation of activated acids in thepresence of a base. The esters described can include produgs that havephenyl esters, aliphatic (C₈-C₂₄) esters, acyloxymethyl esters,carbamates, and amino acid esters (see WO 2010/048712, which isincorporated herein by specific reference in its entirety).

Additionally, prodrugs with increased solubility have been created forcompounds that include secondary and tertiary amine containing drugs.Examples of such prodrugs include N-phosphoryloxymethyl (POM) prodrugswhere the methyl group of the POM moiety is coupled to a secondary ortertiary amine (see U.S. Pat. No. 5,985,856, which is incorporatedherein by specific reference in its entirety).

It has now been found that alternative chemistry techniques can couple aPOM prodrug entity or other POA prodrug entity to ciclopirox in order toform the ciclopirox-POM prodrugs or other ciclopirox-POA prodrugs of thepresent invention. The chemical synthesis protocols can conjugateciclopirox, shown in below, through its hydroxyl group rather thanthrough a secondary or tertiary amine. While ciclopirox does include acyclic nitrogen, it has been found that such a nitrogen is undesirableto be linked to a POA due to the hydroxyl group or oxygen linked to thenitrogen possibly being important for the biological activity ofciclopirox. As such, the present invention provides chemistry techniquesto conjugate a POA moiety to the hydroxyl group that is linked to thering nitrogen of ciclopirox.

In one embodiment, the present invention includes a prodrug ofciclopirox or its derivatives. The prodrug can include a structure ofFormula 1 or derivative thereof or stereoisomer thereof as well as apharmaceutically acceptable salt thereof.

In the formulae, R¹-R⁵ each independently can include a hydrogen,halogens, hydroxyls, alkoxys, straight aliphatics, branched aliphatics,cyclic aliphatics, substituted aliphatics, unsubstituted aliphatics,saturated aliphatics, unsaturated aliphatics, aromatics, polyaromatics,substituted aromatics, hetero-aromatics, amines, primary amines,secondary amines, tertiary amines, aliphatic amines, carbonyls,carboxyls, amides, esters, amino acids, peptides, polypeptides,derivatives thereof, substituted or unsubstituted, or combinationsthereof as well as other well-known chemical substituents. R¹³ and/orR¹⁴ can be a positive ion such as a sodium ion, such that the compoundforms a salt. Also, R¹³ and/or R¹⁴ independently can include a positiveion to form a salt with the prodrug or one or more of hydrogen,halogens, hydroxyls, alkoxys, straight aliphatics, branched aliphatics,cyclic aliphatics, substituted aliphatics, unsubstituted aliphatics,saturated aliphatics, unsaturated aliphatics, aromatics, polyaromatics,substituted aromatics, hetero-aromatics, amines, primary amines,secondary amines, tertiary amines, aliphatic amines, carbonyls,carboxyls, amides, esters, amino acids, peptides, polypeptides, orcombinations thereof. The methyl linker can be expanded to a largeraliphatic group that is substituted or unsubstituted if desired or themethyl may be omitted, such that n can be about 0-20 or 1-20, morepreferably 1-10, and most preferably 1-4. The linker may also have oneor two oxygen atoms, such that m can be 0, 1 or 2. When n is 1, theprodrug moiety is a POM. When n is 2-20, the prodrug moiety is POA.Often, m is 1.

In one embodiment, R¹³ and/or R¹⁴ may independently be any one ofvarious positive ions. In one example, R¹³ and/or R¹⁴ can independentlyinclude ions with positive charge of +1, such as lithium, sodium,potassium, rubidium, cesium, or francium or other complex ion. The R¹³and/or R¹⁴ can be an alkali metal. Also, the R¹³ and/or R¹⁴ canindependently be a group 1 ion, such as a sodium ion or potassium ion.Accordingly, the bond between the oxygen and R¹³ and/or R¹⁴ can becovalent or ionic.

In one embodiment, the R¹³ and/or R¹⁴ can independently be a protectinggroup. Examples of protecting groups can include tert-butyl and benzyl;however, other organic-based protecting groups can be used. Theseprotecting groups may be left on the prodrug for administration, orremoved prior to administration. The R¹³ and/or R¹⁴ may be anysubstituent, such as those recited for R¹ to R¹².

In one embodiment, R¹ is a short aliphatic, such as a methyl or otheralkyl.

In one embodiment, the R²-R¹² are all hydrogen.

In one embodiment, the R¹³ and/or R¹⁴ are each independently a hydrogenor ion.

In one embodiment, the R¹³ and/or R¹⁴ are each independently a benzyl ortert-butyl or other substituent.

In one embodiment, the R¹³ or R¹⁴ includes a ciclopirox-POM or otherciclopirox-POA and the other is hydrogen, which is shown in Formula 10below.

In one embodiment, the present invention can include compounds with astructure of Formula 2 or derivative thereof or stereoisomer thereof.The n, m, R¹, and R¹³ and/or R¹⁴ can be the same as recited above forFormula 1.

In one embodiment, the compounds can include the structure of Formula 3or derivative thereof or stereoisomer thereof. The n, m, R¹, and R¹³and/or R¹⁴ can be the same as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 4or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 5or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 6or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 7or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 8or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 9or derivative thereof or stereoisomer thereof. The n and m can be thesame as recited above for Formula 1.

In one embodiment, the compounds can include the structure of Formula 10or derivative thereof or stereoisomer thereof.

Any of the compounds may be prepared as pharmaceutically acceptablesalts, if possible. Any common pharmaceutically acceptable salt ion canbe used.

Additionally, any of the compounds described herein and represented bythe chemical formulae can have any of the R groups (R¹-R¹⁴)independently selected from substituents selected from the group ofhydrogen, C₁-C₂₄ alkyl, C₂-C₂₄ alkenyl, C₂-C₂₄ alkynyl, C₅-C₂₀ aryl,C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, halo, hydroxyl, sulfhydryl, C₁-C₂₄alkoxy, C₂-C₂₄ alkenyloxy, C₂-C₂₄ alkynyloxy, C₅-C₂₀ aryloxy, acyl(including C₂-C₂₄ alkylcarbonyl (—CO-alkyl) and C₆-C₂₀ arylcarbonyl(—CO-aryl)), acyloxy (—O-acyl), C₂-C₂₄ alkoxycarbonyl (—(CO)—O-alkyl),C₆-C₂₀ aryloxycarbonyl (—(CO)—O-aryl), halocarbonyl (—CO)—X where X ishalo), C₂-C₂₄ alkylcarbonato (—O—(CO)—O-alkyl), C₆-C₂₀ arylcarbonato(—O—(CO)—O-aryl), carboxy (—COOH), carboxylato (—COO⁻), carbamoyl(—(CO)—NH₂), mono-(C₁-C₂₄ alkyl)-substituted carbamoyl (—(CO)—NH(C₁-C₂₄alkyl)), di-(C₁-C₂₄ alkyl)-substituted carbamoyl (—(CO)—N(C₁-C₂₄alkyl)₂), mono-substituted arylcarbamoyl (—(CO)—NH-aryl), thiocarbamoyl(—(CS)—NH₂), carbamido (—NH—(CO)—NH₂), cyano(—C≡N), isocyano (—N⁺≡C⁻),cyanato (—O—C≡N), isocyanato (—O—N⁺≡C⁻), isothiocyanato (—S—C≡N), azido(—N═N⁺═N⁻), formyl (—(CO)—H), thioformyl (—(CS)—H), amino (—NH₂), mono-and di-(C₁-C₂₄ alkyl)-substituted amino, mono- and di-(C₅-C₂₀aryl)-substituted amino, C₂-C₂₄ alkylamido (—NH—(CO)-alkyl), C₆-C₂₀arylamido (—NH—(CO)-aryl), imino (—CR═NH where R is hydrogen, C₁-C₂₄alkyl, C₅-C₂₀ aryl, C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), alkylimino(—CR═N(alkyl), where R=hydrogen, alkyl, aryl, alkaryl, aralkyl, etc.),arylimino (—CR═N(aryl), where R=hydrogen, alkyl, aryl, alkaryl, etc.),nitro (—NO₂), nitroso (—NO), sulfo (—SO₂—OH), sulfonato (—S₂—O⁻), C₁-C₂₄alkylsulfanyl (—S-alkyl; also termed “alkylthio”), arylsulfanyl(—S-aryl; also termed “arylthio”), C₁-C₂₄ alkylsulfinyl (—(SO)-alkyl),C₅-C₂₀ arylsulfinyl (—(SO)-aryl), C₁-C₂₄ alkylsulfonyl (—SO₂-alkyl),C₅-C₂₀ arylsulfonyl (—SO₂-aryl), phosphono (—P(O)(OH)₂), phosphonato(—P(O)(O⁻)₂), phosphinato (—P(O)(O—)), phospho (—PO₂), phosphino (—PH₂),derivatives thereof, and combinations thereof.

The POM prodrug moiety of a prodrug compound can be cleaved off by anymechanism, such as hydrolysis or enzymatically to result in the POMcompound and a biologically active compound. Thus, a method of forming abiologically active compound in a subject can include administering theprodrug compound.

Any POA prodrug moiety of a prodrug compound can be cleaved off by anymechanism, such as hydrolysis or enzymatically to result in the POAcompound and a biologically active compound. Thus, a method of forming abiologically active compound in a subject can include administering theprodrug compound.

Pharmaceutical Compositions

In one embodiment, the ciclopirox-POM prodrug or other ciclopirox-POAprodrug can be included in a pharmaceutical composition. Thepharmaceutical compositions can be formulated to be suitable for theroute of administration, such as intravenous, subcutaneous, oral, ortopical.

In one embodiment, a pharmaceutical composition can include theciclopirox-POM prodrug as described herein. For example, thepharmaceutical composition can include a pharmaceutically acceptablecarrier. Since the ciclopirox-POA prodrug is now highly water soluble,the pharmaceutically acceptable can include water. However, the carriercan be sufficient in order to administer the ciclopirox-POA prodrug sothat it reaches the aqueous environment of a subject to which it isadministered, such as a human of the cells thereof.

In one embodiment, the pharmaceutical composition can include theciclopirox-POM prodrug being present in an amount greater than about0.77%, more preferably greater than about 1%; or most preferably greaterthan about 2%.

In one embodiment, the pharmaceutical composition can include water as acarrier.

The compositions described herein can be prepared by per se knownmethods for the preparation of pharmaceutically acceptable compositionsthat can be administered to subjects, such that an effective quantity ofthe active substance is combined in a mixture with a pharmaceuticallyacceptable vehicle. Suitable vehicles are described, for example, inRemington's Pharmaceutical Sciences. On this basis, the compositionsinclude, albeit not exclusively, solutions of the substances inassociation with one or more pharmaceutically acceptable vehicles ordiluents, and contained in buffered solutions with a suitable pH andiso-osmotic with the physiological fluids.

In one embodiment, the effective amount of ciclopirox-POA prodrug iswithin the range of about 1 to about 200 mg/kg body weight of a subject.In one aspect, the effective amount of ciclopirox-POA prodrug is withinthe range of about 5 to about 50 mg/kg body weight. The ciclopirox-POAprodrug can be prepared into a solid dosage form that contains fromabout 20 mg to about 1000 mg of ciclopirox-POA prodrug. In one aspect,the composition can include about 20 mg to about 200 mg ofciclopirox-POA prodrug/kg body weight of subject, and can be formulatedinto a solid oral dosage form, a liquid dosage form, or an injectabledosage. However, other amounts can be used. For example, the drug can beadministered over a wide range of doses, such as 0.5 mg/m² to 300 mg/m²,1 mg/m² to 200 mg/m², 5 mg/m² to 150 mg/m², 10 mg/m² to 75 mg/m², or anysuitable amount.

In one embodiment, the present invention can include a pharmaceuticalcomposition configured for treatment of a leukemic disorder. Such acomposition can include an effective amount of ciclopirox-POA prodrugthat can be administered orally or intravenous or other injection.

Pharmaceutical compositions include, without limitation, lyophilizedpowders or aqueous or non-aqueous sterile injectable solutions orsuspensions, which may further contain antioxidants, buffers,bacteriostats and solutes that render the compositions substantiallycompatible with the tissues or the blood of an intended recipient. Othercomponents that may be present in such compositions include water,surfactants (e.g., Tween®), alcohols, polyols, glycerin and vegetableoils, for example. Extemporaneous injection solutions and suspensionsmay be prepared from sterile powders, granules, tablets, or concentratedsolutions or suspensions. The composition may be supplied, for examplebut not by way of limitation, as a lyophilized powder which isreconstituted with sterile water or saline prior to administration tothe patient.

Suitable pharmaceutically acceptable carriers include essentiallychemically inert and nontoxic compositions that do not interfere withthe effectiveness of the biological activity of the pharmaceuticalcomposition. Examples of suitable pharmaceutical carriers include, butare not limited to, water, saline solutions, glycerol solutions,ethanol, N-(1 (2,3-dioleyloxy)propyl)N,N,N-trimethylammonium chloride(DOTMA), diolesyl-phosphotidyl-ethanolamine (DOPE), and liposomes. Suchcompositions should contain a therapeutically effective amount of thecompound, together with a suitable amount of carrier so as to providethe form for direct administration to the patient.

The compositions described herein can be administered for example, byparenteral routes of administration such as intravenous, subcutaneous,intramuscular, intracranial, intraorbital, ophthalmic, intraventricular,intracapsular, intraspinal, intracisternal, intraperitoneal, intranasal,aerosol or oral administration. Common carriers or excipients can beused for preparing pharmaceutical compositions designed for such routesof administration.

Another aspect provides a commercial package comprising a compositiondescribed herein, and associated therewith instructions for the usethereof for treatment of a disorder for which ciclopirox is effective,such as those described herein. For example, the package can include asuitable amount for treating a leukemic disorder, such as acute myeloidleukemia or acute lymphoid leukemia, in a subject in need of suchtreatment. In another embodiment. The commercial package can includeinstructions for administration and/or a therapeutic regimen for thetreatment of chronic myelogenous leukemia, lymphoma or multiple myeloma.Another embodiment provides a commercial package comprising acomposition described herein, and associated therewith instructions forthe inducing cell death and/or inhibiting surviving activity or level ina leukemic disorder cell such as a leukemia cell.

In one embodiment, the composition is devoid of an olamine. In fact, theprodrug can be devoid of an olamine. Accordingly, the composition can bedevoid of a ciclopirox olamine or derivative thereof.

In one embodiment, the prodrug can be present in a therapeuticallyeffective amount for use as a therapy. For example, the therapeuticallyeffective amount can be sufficient for one or more of the following: foruse in treatment of a fungus; for use in treatment of cancer; for use intreatment of dermatitis; for disrupting DNA repair, cell division, orintranuclear transport in a cell; for use in treatment of superficialmycoses; for use as an anti-inflammatory; for use in treatment of one ormore of tinea pedis, tinea cruris, and tinea corporis, Trichophytonrubrum, Trichophyton mentagrophytes, Epidermophyton floccosum, andMicrosporum canis, candidiasis (moniliasis), Candida albicans, tinea(pityriasis) vesicolor, or Malassezia furfur; for use in treating acutemyeloid leukemia or acute lymphoid leukemia; chronic myelogenousleukemia, lymphoma or multiple myeloma, or others.

In one embodiment, a method of forming a compound in a subject caninclude: providing a composition having a prodrug compound representedby a structure of Formula 1 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof; and administering the composition to a subjectsuch that the prodrug compound has a phosphoryloxymethyl prodrug moietyremoved therefrom to form the compound in the subject. Formula 1 is thesame as provided herein. The R groups e.g., R¹-R¹⁵, can be as describedherein or independently any one or more of the substituents selectedfrom the group of hydrogen, C₁-C₂₄ alkyl, C₂-C₂₄ alkenyl, C₂-C₂₄alkynyl, C₆-C₂₀ aryl, C₇-C₂₄ alkaryl, C₇-C₂₄ aralkyl, halo, hydroxyl,sulfhydryl, C₁-C₂₄ alkoxy, C₂-C₂₄ alkenyloxy, C₂-C₂₄ alkynyloxy, C₆-C₂₀aryloxy, acyl (including C₂-C₂₄ alkylcarbonyl (—CO-alkyl) and C₇-C₂₀arylcarbonyl (—CO-aryl)), acyloxy (—O-acyl), C₂-C₂₄ alkoxycarbonyl(—(CO)—O-alkyl), C₇-C₂₀ aryloxycarbonyl (—(CO)—O-aryl), halocarbonyl(—CO)—X where X is halo), C₂-C₂₄ alkylcarbonato (—O—(CO)—O-alkyl),C₇-C₂₀ arylcarbonato (—O—(CO)—O-aryl), carboxy (—COOH), carboxylato(—COO⁻), carbamoyl (—(CO)—NH₂), mono-(C₁-C₂₄ alkyl)-substitutedcarbamoyl (—(CO)—NH(C₁-C₂₄ alkyl)), di-(C₁-C₂₄ alkyl)-substitutedcarbamoyl (—(CO)—N(C₁-C₂₄ alkyl)₂), mono-substituted arylcarbamoyl(—(CO)—NH-aryl), di-substituted arylcarbamoyl (—(CO)—NH-aryl)₂,thiocarbamoyl (—(CS)—NH₂), mono-(C₁-C₂₄ alkyl)-substituted thiocarbamoyl(—(CS)—NH(C₁-C₂₄ alkyl)), di-(C₁-C₂₄ alkyl)-substituted thiocarbamoyl(—(CS)—N(C₁-C₂₄ alkyl)₂), mono-substituted arylthiocarbamoyl(—(CS)—NH-aryl), di-substituted arylthiocarbamoyl (—(CS)—NH-aryl)₂,carbamido (—NH—(CO)—NH₂),), mono-(C₁-C₂₄ alkyl)-substituted carbamido(—NH—(CO)—NH(C₁-C₂₄ alkyl)), di-(C₁-C₂₄ alkyl)-substituted carbamido(—NH—(CO)—N(C₁-C₂₄ alkyl)₂), mono-substituted aryl carbamido(—NH—(CO)—NH-aryl), di-substituted aryl carbamido (—NH—(CO)—N-(aryl)₂)cyano(—C≡N), isocyano (—N⁺≡C⁻), cyanato (—O—C≡N), isocyanato (—O—N⁺≡C⁻),thiocyanato (—S—C≡N), isothiocyanato (—S—N⁺≡C⁻), azido (—N═N⁺═N⁻),formyl (—(CO)—H), thioformyl (—(CS)—H), amino (—NH₂), mono- anddi-(C₁-C₂₄ alkyl)-substituted amino, mono- and di-(C₆-C₂₀aryl)-substituted amino, C₂-C₂₄ alkylamido (—NH—(CO)-alkyl), C₆-C₂₀arylamido (—NH—(CO)-aryl), imino (—CR═NH where R is hydrogen, C₁-C₂₄alkyl, C₆-C₂₀ aryl, C₇-C₂₄ alkaryl, C₇-C₂₄ aralkyl, etc.), alkylimino(—CR═N(alkyl), where R=hydrogen, C₁-C₂₄ alkyl, aryl, alkaryl, aralkyl,etc.), arylimino (—CR═N(aryl), where R=hydrogen, alkyl, aryl, alkaryl,etc.), nitro (—NO₂), nitroso (—NO), sulfonic acid (—SO₂—OH), sulfonato(—SO₂—O⁻), C₁-C₂₄ alkylsulfanyl (—S-alkyl; also termed “alkylthio”),C₆-C₂₀ arylsulfanyl (—S-aryl; also termed “arylthio”), C₁-C₂₄alkylsulfinyl (—(SO)-alkyl), C₆-C₂₀ arylsulfinyl (—(SO)-aryl), C₁-C₂₄alkylsulfonyl (—SO₂-alkyl), C₆-C₂₀ arylsulfonyl (—SO₂-aryl), phosphono(—P(O)(OH)₂), phosphonato (—P(O)(O⁻)₂), phosphinato (—P(O)(O—)), phospho(—PO₂), phosphino (—PH₂), any with or without hetero atoms (e.g., N, O,P, S, or other) where the hetero atoms can be substituted (e.g., heteroatom substituted for carbon in chain or ring) for the carbons or inaddition thereto (e.g., hetero atom added to carbon chain or ring)swapped, derivatives thereof, and combinations thereof.

In one embodiment, the prodrug moiety is cleaved from the prodrugcompound. Such a prodrug moiety can be a phosphoryloxymethyl prodrugmoiety, such as having a structure of Formula 11:

wherein: R¹⁵ includes one or more of a positive ion, sodium ion,hydrogen, halogens, hydroxyls, alkoxys, straight aliphatics, branchedaliphatics, cyclic aliphatics, substituted aliphatics, unsubstitutedaliphatics, saturated aliphatics, unsaturated aliphatics, aromatics,polyaromatics, substituted aromatics, hetero-aromatics, amines, primaryamines, secondary amines, tertiary amines, aliphatic amines, carbonyls,carboxyls, amides, esters, amino acids, peptides, polypeptides,substituted or unsubstituted, or combinations thereof. In one example,R¹⁵ results from enzymatic cleavage of the prodrug compound.

In one example, R¹⁵ is hydrogen. It is thought that it is possible inthe subject that the POA or POM may conjugate with other substances whencleaved from the ciclopirox or derivative thereof, which may form a widevariety of POA compounds or form POM. In one aspect, thephosphoryloxyalkyl prodrug moiety has a structure of Formula 11A. In oneaspect, the phosphoryloxymethyl prodrug moiety has a structure ofFormula 11B.

In one embodiment, R¹⁵ includes one or more of hydrogen, halogen,hydroxyls, alkoxys, straight aliphatics, branched aliphatics, cyclicaliphatics, substituted aliphatics, unsubstituted aliphatics, saturatedaliphatics, unsaturated aliphatics, amines, primary amines, secondaryamines, tertiary amines, aliphatic amines, carbonyls, carboxyls, amides,esters, amino acids, peptides, polypeptides, substituted orunsubstituted, or combinations thereof.

In one embodiment, R¹⁵ includes one or more of hydrogen, halogen,hydroxyls, alkoxys, straight aliphatics, branched aliphatics, cyclicaliphatics, substituted aliphatics, unsubstituted aliphatics, saturatedaliphatics, unsaturated aliphatics, amino acids, peptides, polypeptides,substituted or unsubstituted, or combinations thereof.

In one embodiment, R¹⁵ includes one or more of hydrogen, halogen,hydroxyls, alkoxys, straight aliphatics, branched aliphatics, cyclicaliphatics, substituted aliphatics, unsubstituted aliphatics, saturatedaliphatics, unsaturated aliphatics, or combinations thereof.

In one embodiment, the active compound resulting from the prodrugcompound can be any of the compounds described herein, such as theciclopirox compounds, such as derivatives of Formulae 2-10 that lack theprodrug moiety. It should be noted that the ions for the POA or POM canbe any appropriate cation or combinations of cations, such as anymonovalent cation, such as sodium or potassium, and possibly lithium orthe like. In one embodiment, the active compound that results from theprodrug compound can have a structure of Formula 12.

For Formula 12, the R groups (e.g., R¹-R¹²) can be as defined herein. Inone example, R¹ is an alkyl (e.g., methyl) and R²-R¹² are hydrogen, suchas ciclopirox.

In one embodiment, the phosphoryloxymethyl prodrug moiety isenzymatically cleaved from the prodrug compound so as to form thecompound.

In one embodiment, the phosphoryloxyalkyl prodrug moiety isenzymatically cleaved from the prodrug compound so as to form thecompound.

In one embodiment, the compound is formed in an amount sufficient fordisrupting DNA repair in a cell in the subject.

In one embodiment, the compound is formed in an amount sufficient fordisrupting cell division in the subject.

In one embodiment, the compound is formed in an amount sufficient fordisrupting intranuclear transport in a cell in the subject.

The prodrug compound can be used to treat different cancers, such asbladder cancer. The treatment of bladder cancer with the prodrugcompound is described in PCT/US2015/0059955 filed Nov. 10, 2015, whichis incorporated herein by specific reference in its entirety. Theexperimental section, figures, tables and all other data ofPCT/US2015/0059955 is specifically incorporated as it shows the prodrugcompound is cleaved into the active compound and the POA (e.g., (POM)compound. Also, U.S. Provisional Patent Application 62/134,747 filedMar. 18, 2015 and U.S. Provisional Patent Application 62/078,069 filedNov. 11, 2014 are incorporated herein by specific reference in theirentireties.

It has now been found that the compounds of the present invention areuseful for treating bladder cancer. The bladder cancer can include NMIBC(non-muscle invasive bladder cancer) and MIBC (Muscle invasive bladdercancer), as well as other bladder cancers. Giving the prodrug bysystemic injection (e.g., intravenous, intramuscular, subcutaneous,etc.) results in active, clinically relevant concentrations (e.g.,significant concentrations) of the active agent ciclopirox beingselectively delivered to the entire urinary tract. This can treatnon-muscle invasive or superficial bladder cancer.

The prodrug converts to the active ciclopirox compound that effectivelysuppresses stem cells in bladder cancer and specifically targets theNotch-1 signaling pathway. It has been demonstrated that in the presenceof the compound, signaling is significantly suppressed and the compoundis affecting bladder cancer through this mechanism. Suppressing Notch isa significant activity for the compound to inhibit bladder and othercancers where Notch signaling is active (e.g. colon cancer,osteosarcoma).

NMIBC starts out by a cancer of the outer lining (urothelium) of theurinary tract (e.g., the lining that's up against the urine), and thecancer cells that are on the outer lining start invading inwardly intothe muscle of the bladder, and then the cancer spreads throughout thebody. However, the activity of ciclopirox and the delivery as theprodrug allows the drug to inhibit a pathway that is associated with theinvasiveness of this particular cancer.

In one embodiment, the prodrug can be administered to provide theanticancer activity of ciclopirox to treat leukemia, lymphoma,colorectal cancer, hepatoma, rhabdomyosarcoma, and breast cancer celllines, as well as others, such as but not limited to pancreatic cancer,renal cell carcinoma, hematologic malignancies, cervical cancer,myeloma, and possibly others.

Accordingly, the ciclopirox-POA can be used against a broad spectrum ofcancer lines by disrupting DNA repair, cell division, or intranucleartransport in a cell, by inhibiting Notch signaling, and inhibiting anyother biological pathway described herein.

The ciclopirox-POM prodrug, based on activity of ciclopirox, may also beused to induce autophagy, inhibit mTOR, downregulate cyclins A, B 1, D1and E as well as CDK2 and CDK4, and other activities.

The methods of treating bladder cancer with the prodrug can includeadministering ciclopirox-POM prodrug (e.g., prodrug) systemically forthe treatment of bladder cancer, which provides surprising andunexpected results, such as described herein.

It has been found that systemic administration of ciclopirox-POM prodrugresults in the selective delivery of clinically significantconcentrations of the active, anticancer agent, ciclopirox (free acid)to the entire urinary tract.

Current treatment of non-muscle invasive bladder cancer (NMIBC, formerlyreferred to as superficial bladder cancer) is via bladder instillation.There are no current drug therapies for NMIBC administered by any routeother than bladder instillation. Bladder instillation of anticanceragents only exposes bladder cancer to anticancer agents for the periodof time patients are able to retain fluids in their bladders (e.g., twohours). Secondly, bladder instillation does not deliver drug to theentire urinary tract, i.e., the ureters, collecting system, and kidneysthat anatomically sits above the bladder. Up to 10% of NMIBC patientshave upper urinary tract disease. Contrary thereto, the presentinvention includes systemic delivery (e.g., injection) that providesactive drug to the entire urinary tract. However, the therapeutics mayalso be delivered by bladder installation.

Bladder cancer presents as two diseases, NMIBC and muscle invasivebladder cancer (MIBC). Approximately three-fourths of newly diagnosedbladder cancer patients present with NMIBC. NMIBC, as it invades intobladder muscle, becomes MIBC. MIBC often metastasizes, requiringsystemically administered chemotherapy agents. It has now beensurprising and unexpectedly demonstrated that ciclopirox possessesanticancer activity in NMIBC and MIBC bladder cancers, and systemicdelivery of ciclopirox-POM prodrug provides the ciclopirox to thesebladder cancer cells. The ciclopirox from ciclopirox-POM prodrugdelivery inhibits cell proliferation, colony formation, and spheroidformation in well characterized NMIBC and MIBC cell lines. Although thatciclopirox's fungicidal activity is mediated through its ability tochelate iron, and interrupt iron-dependent intracellular processes,ciclopirox in vitro anti-cancer activity in independent of commerciallyavailable iron chelators. For the first time, it was demonstrated thatciclopirox inhibits the Notch-1 signaling pathway, which is a pathwayrecently identified as being overexpressed in invasive bladder cancer,and a pathway that is overexpressed in cancer stem cells across a numberof cancers. Accordingly, ciclopirox-POM prodrug can be used in treatmentof all forms of bladder cancer, and in cancer stem cells of manydifferent cancers where the Notch signaling pathway is active.

The improved solubility of the ciclopirox-POA prodrug can now allow forimproved pharmaceutical compositions for administering effective amountsof ciclopirox by injection. The pharmaceutical compositions can beformulated to be suitable for injectable routes of administration, suchas intravenous, subcutaneous, and intramuscular.

Synthesis

Generally, ciclopirox can be obtained and then reacted through thereaction protocols described herein in order to produce theciclopirox-POM prodrug. Also, a ciclopirox derivative can be obtainedand reacted following the synthetic protocols described herein, where aciclopirox derivative reagent will result in a correspondingciclopirox-POM derivative prodrug. In some instances, the ciclopirox orderivative thereof can be obtained in a salt, such as an olamine salt.Accordingly, the reaction scheme can include desalting the ciclopiroxprior to conjugation with the POM prodrug moiety. However, the reagentscan substitute an alkyl for the methyl so that the POA prodrug moietycan be conjugated to ciclopirox.

In the figures and associated following descriptions of chemicalreactions and the corresponding reactants, abbreviations are used todescribe chemicals, which abbreviations are defined as follows: EDAC isN-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride; DIAD isdiisopropyl azodicarboxylate; BBDI is1-tert-Butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline; DICD isdiisopropyl carbodiimide; and DBP is dibenzyl phosphate.

In one embodiment, the present invention provides a method of preparing6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one, which method caninclude reaction Scheme 1 as shown in FIG. 1. The reaction of Scheme 1prepares a ciclopirox from an olamine salt thereof. Briefly, ciclopiroxolamine (5 g, 18.6 mmol) can be dissolved in 2 N HCl, extracted withEtOAc, and precipitated with hexane in order to obtain ciclopirox (aboutan 84% yield).

In one embodiment, the present invention provides a method of preparinga reagent for use in preparing a prodrug of6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one, which method caninclude reaction Scheme 2 as shown in FIG. 2. The reaction Scheme 2provides a reagent for preparation of a reagent of the POM prodrugmoiety, which is di-tert-butyl(chloromethyl)phosphate. Briefly,potassium di-tert phosphate (5 g, 20 mmol) is dissolved in a minimumamount of cold water and 6 N HCl is added drop-wise in order to form aprecipitate, and then the precipitate is washed with cold water, whichis then filtered and dried under vacuum in order to form di-tertphosphate. The di-tert-phosphate (4 g, 19 mmol) is then dissolved inabout 100 mL acetone with tetramethylammonium hydroxide added drop-wiseuntil reaching about pH 7, and then the solvent is removed and driedunder vacuum to produce tetra-methyl ammonium di-tert-butyl phosphate.Tetra-methyl ammonium di-tert-butyl phosphate (5.11 g, 18 mmol) is thenreacted with iodocholoro methane (CH₂ClI) (25 g, 142 mmol, 7.88equivalent) in about 150 ML DME and refluxed for about 2 hours beforebeing filtered to remove the precipitate, removal of the solvent, andthen dissolved in EA/H, and then filtered through a silica bed, and thesolvent is removed and the product is dried to obtaindi-tert-butyl(chloromethyl)phosphate. A TLC is shown to confirm product.

In one embodiment, the present invention provides a method of preparinga prodrug of 6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one (i.e.,((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate disodiumsalt), which method can include reaction Scheme 3 as shown in FIG. 3.The reaction Scheme 3 reacts ciclopirox withdi-tert-butyl(chloromethyl)phosphate to form a ciclopirox-POM thatincludes a disodium salt. Briefly, ciclopirox (0.257 g, 1.25 mmol) anddi-tert-butyl(chloromethyl)phosphate (0.450 g, 1.74 mmol) are dissolvedin 5 mL and reacted with 60% NaH (0.62 g, 154. mmol) at 0° C. for 30minutes and then room temperature for 2 hours before being quenched withwater, and then the solvent is removed and process through a separationcolumn with EA/H (1:1) to yield di-tert-butyl(((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl) phosphate, whichwas confirmed via TLC. The di-tert-butyl(((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl) phosphate was thendissolved in 10 mL THF/CH₂Cl₂ (3:1), and incubated at room temperaturefor 2 hours before the solvent was removed and purified via RPHPLC, andthen equamolar Na₂CO₃ in water/ACN was added and lyophilized to obtain((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphate(14 mg, 0.044 mmol) and((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate disodiumsalt (15.89 mg), which is referred to herein as the primaryciclopirox-POM prodrug.

FIG. 3A shows a sub-reaction process identified as Scheme 3A, which canbe a sub-process of Scheme 3. Scheme 3A shows the di-tert-butyl(((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl) phosphateconverting to tert-butyl(((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl) hydrogen phosphate,which converts to((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyldihydrogen phosphate.FIG. 3B shows a mass spectrometry chromatograph that shows the presenceof these chemical entities.

The free acid form of the ciclopirox-POM prodrug (i.e.,((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphate)was also purified by RPHPLC as shown in FIG. 3C. The purified productwas shown to have a mass spectrometry chromatograph as shown in FIG. 3C.

Additionally, another dimer-type form of ciclopirox-POM prodrug has beencreated as shown in FIG. 3D, which is referred to as the ciclopirox-POMdimer prodrug. The ciclopirox-POM dimer prodrug is confirmed with massspectrometry chromatograph as shown in FIG. 3E.

FIG. 4 illustrates Scheme 4 which is the process of salting((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphatewith sodium ions in order to obtain((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate disodiumsalt, which is confirmed with mass spectrometry chromatograph as shownin FIG. 4A.

In one embodiment, the present invention can include a method ofpreparing the POM reagent dibenzyl(chloromethyl)phosphate, as shown inreaction Scheme 5 of FIG. 5. Briefly, CH₂ClI (5 mL; 68.6 mmol) isreacted with silver dibenzyl phosphate (2 g, 52 mmol) in about 25 mLtoluene and refluxed for about 1 hour before the solvent is removed andprocessed through a separation column with 1/1EA/H in order to producedibenzyl(chloromethyl)phosphate as confirmed via TLC.

In one embodiment, the present invention provides a method of preparinga prodrug dibenzyl(((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl) phosphate,which is shown by Scheme 6 of FIG. 6. Briefly, ciclopirox (0.431 g, 2.08mmol) is dissolved in 10 mL DMF with dibenzyl(chloromethyl)phosphate(0.920 g, 2.81 mmol) along with 60% NaH (0.096 g, 2.38 mmol) andincubated at 0° C. for 30 minutes and then at room temperature for 1hour before being quenched with water. The solvent is then removed andprocessed through a separation column with EA/H 1:1 in order to yielddibenzyl (((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl)phosphate, which is confirmed via the TLC as shown.

In one embodiment, dibenzyl(((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl) phosphate isconverted into ((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methylphosphate disodium salt as shown in Scheme 7 of FIG. 7. Briefly,dibenzyl (((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl)phosphate is dissolved in 25 mL THF in the presence of 100 mg Pd/C, andunder hydrogen (H₂) at room temperature for 3 hours before the solventwas removed and the product dissolved in ACN. Na₂CO₃ in water is thenadded and lyophilized. The product is determined to be a minor amount of((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl dihydrogen phosphate(about 0.273 g, 0.86 mmol) and the major product being((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate disodiumsalt (0.310 g), which was confirmed via TLC as shown.

In one embodiment, another method of preparing the POM reagentdibenzyl(chloromethyl)phosphate, as shown in reaction Scheme 8 of FIG.8. Briefly, dibenzylphosphate (10.6 g; 38.08 mmol) and chloromethylsulfochloridate (7.52 g, 456.6 mmol/120 mL CH₂Cl₂) are dissolved in 320mL water and 200 mL CH₂Cl₂ with NaHCO₃ (12.80 g, 152.32 mmol) andn-Bu₄NHSO₄ (12.94 g, 38.08 mmol) at 0° C. to room temperature overnight,and then processed through a separation column with ½ EA/H, EA. Thisreaction yields about 48% of dibenzyl(chloromethyl)phosphate (6 g),which is confirmed with TLC as shown.

In one embodiment, the present invention provides another method ofpreparing a prodrug dibenzyl(((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl) phosphate,which is shown by Scheme 6 of FIG. 6. Briefly, Ciclopirox (1 g, 4.82mmol) is dissolved in 20 mL DMF with dibenzyl(chloromethyl)phosphate (2g, 6.12 mmol) along with 60% NaH (0.375 g) and incubated at 0° C. for 30minutes and then at room temperature for 1 hour before being quenchedwith water. The solvent is then removed, and the product is dissolved inEtOAc, washed with water, solvent is removed, and processed through aseparation column with EA/H 1:2, and RPHPLC in order to yield 67%dibenzyl (((6-cyclohexyl-4-methyl-2-oxopyridin-1(2H)-yl)oxy)methyl)phosphate (1.616 g).

Experimental

The data in the figures and tables indicates that ciclopirox-POM prodrugas described herein can be an improvement for administration tosubjects. It was found that ciclopirox was readily bioavailable whengiven IV as the prodrug, compared to IV administration of ciclopiroxolamine to mice, rats and dogs, and thereby the ciclopirox-POM is animprovement in chemical formulation. Following oral administration tomice, however, bioavailability is low, 21% following administration ofthe olamine salt, and 12% following oral administration ofciclopirox-POM prodrug. Accordingly, ciclopirox is readily bioavailablewhen given IV as the prodrug. Based on the inability to detect theprodrug in plasma and urine following IV, oral, subcutaneous andintraperitoneal administration, it appears the prodrug is rapidly andcompletely metabolized to ciclopirox when it reaches the systemiccirculation. Thus, ciclopirox-POM prodrug has advantages over ciclopiroxolamine, from a physicochemical properties standpoint, and can beformulated into a suitable injectable product. Based on the data, it isreasonable to believe that the ciclopirox-POM prodrug is rapidlyconverted to ciclopirox.

The ciclopirox-POM prodrug described herein(((6-cyclohexyl-4-methylpyridin-1(2H)-yl)oxy)methyl phosphate disodiumsalt, MW 361) was studied and compared with the ciclopirox free base (MW207) and ciclopirox olamine (MW 268). Equivalent doses of ciclopirox forthese three entities were administered such as follows: ciclopiroxolamine at 2.0 mg/mL and ciclopirox-POM prodrug at 2.69 mg/mL. Theplasma ciclopirox concentrations in (ng/mL) were determined followingbolus administration of ciclopirox-POM prodrug at a 10 mg/kg IV bolus ina mouse model. Time points where data collected are shown in Table 1 tobe at 5, 15, 30, 60, 90, 120, 180, and 240 minutes along with the data.Additional Samples were collected were collected at 360, 480, 720 and1440 minutes, however, concentrations fell below BQL of 10 ng/mL, andare not included in PK data analysis. The IV bolus formulation forprodrug was in 25 mM phosphate buffer.

TABLE 1 Plasma Ciclopirox Concentrations (ng/mL): Ciclopirox-POM IVBolus Time (min) A B C D E F Mean SD % CV 5 7280 7320 6370 9700 85008860 8005 1226.1 15.3 15 3310 3180 1520 1370 4010 3190 2763.3 1067.338.6 30 994 1200 986 1030 1080 452 957 259.5 27.1 60 410 259 284 259 409436 342.8 83.8 24.4 90 97.6 157 74.2 79.1 162 168 123 43.9 35.7 120 5873.7 57.9 19.3 71.7 84.8 60.9 22.8 37.4 180 18.1 23 19.5 34.8 19.7 37.725.5 8.6 33.6 240 13 10 15 12 10 8 11.1 2.6 23.6

The plasma ciclopirox concentrations in (ng/mL) were determinedfollowing bolus administration of ciclopirox olamine at a 10 mg/kg IVbolus in a mouse model. Time points where data collected are shown inTable 1 to be at 5, 15, 30, 60, 90, 120, 180, and 240 minutes along withthe data. The IV bolus formulation for ciclopirox olamine was in 0.05 MCaptisol® and 25 mM phosphate buffer, and the corresponding data isshown below in Table 2. Additional Samples were collected were collectedat 360, 480, 720 and 1440 minutes, however, concentrations fell belowBQL of 10 ng/mL, and are not included in PK data analysis

TABLE 2 Plasma Ciclopirox Concentrations (ng/mL): Ciclopirox Olamine IVBolus Time (min) A B C D E F Mean SD % CV 5 6090 3490 5830 4480 39305430 4875 1064.3 21.8 15 543 591 1410 1100 739 968 891.8 332.6 37.3 30545 371 166 339 336 364 353.5 120.6 34.1 60 171 127 124 144 110 124133.3 21.4 16.1 90 45.2 63.4 58.8 42.9 58 84 58.7 14.8 25.2 120 46.141.2 46.9 39.2 42.4 OL 43.2 17.6 48.9 180 14 18.9 18.1 28.7 47.2 24.525.2 11.9 47.3 240 12 12 21 16 OL 19 15.9 4.2 26.6

The plasma ciclopirox (i.e., CPX) concentrations in (ng/mL) weredetermined following bolus administration of ciclopirox-POM prodrug at a30 mg/kg orally in a mouse model. Time points where data collected areshown in Table 3 to be at 5, 15, 30, 60, 90, 120, 180, and 240 minutesalong with the data. Additional Samples were collected were collected at360, 480, 720 and 1440 minutes, however, concentrations fell below BQLof 10 ng/mL, and are not included in PK data analysis. The oralformulation is a composition having Orasweet SF along with theciclopirox-PIM prodrug.

TABLE 3 Plasma Ciclopirox Concentrations (ng/mL): Ciclopirox-POM OralDose Time % (min) A B C D E F Mean SD CV 0 0 0 0 0 0 0 0 ND ND 15 388646 857 245 479 507 520.3 211.8 40.7 30 302 252 264 317 207 342 280.749.1 17.5 60 129 404 154 229 171 207 215.7 99 45.9 90 91 66.8 146 137120 80.3 106.9 32.2 30.1 120 72.5 60.6 64.6 81.4 83.6 OL 72.5 39.6 54.6180 36.8 45.1 59.1 66.4 44.9 44 49.4 11 22.4 240 9.51 OL 19 14.7 38.1 1920.1 10.8 53.9

The plasma ciclopirox concentrations in (ng/mL) were determinedfollowing bolus administration of ciclopirox olamine at a 30 mg/kg oraldose in a mouse model. Time points where data collected are shown inTable 1 to be at 5, 15, 30, 60, 90, 120, 180, and 240 minutes along withthe data. The oral formulation for ciclopirox olamine was a suspensionof Orasweet SF, and the corresponding data is shown below in Table 4.Additional Samples were collected were collected at 360, 480, 720 and1440 minutes, however, concentrations fell below BQL of 10 ng/mL, andare not included in PK data analysis

TABLE 4 Plasma Ciclopirox Concentrations (ng/mL): Ciclopirox OlamineOral Dose Time (min) A B C D E F Mean SD % CV 0 0 0 0 0 0 0 0 ND ND 15478 OL 625 445 565 626 547.8 83.4 15.2 30 427 376 430 432 388 641 449 9721.6 60 379 319 501 211 246 196 308.7 116.8 37.8 90 124 297 259 348 337198 260.5 86.5 33.2 120 OL 101 146 85.4 204 218 150.9 59.4 39.4 180 78.283.4 76.4 107 66.5 69.2 80.1 14.5 18.1 240 72.3 93.1 92.5 48.9 67.8 73.674.7 16.6 22.2

Additionally, mouse intravenous dose pharmacokinetics were determined.Briefly, the pharmacokinetics were determined for mouse hepatic bloodflow at 90 mL/min/kg, an ciclopirox would be considered a mediumclearance drug with extraction ration of 0.6 The IV boluspharmacokinetics are shown in Table 5 below.

TABLE 5 Ciclopirox Pharmacokinetics (10 mg/kg IV Bolus) CPX Prodrug CPXOlamine PK Parameter mg/kg 10 mg/kg Alpha rate constant (min−1) 0.070430.08802 Alpha Half-life (min) 9.84 7.87 Beta rate constant (min−1)0.01929 0.01208 Beta Half-life (min) 35.92 57.35 AUC (ng/mL/kg) 160330140313 CL (mL/min/kg) 48.275* 55.162* Vdbeta (mL/kg) 2502 4565.2

Additionally, mouse oral dose pharmacokinetics were determined. Briefly,the pharmacokinetics were determined for mouse hepatic blood flow at 90mL/min/kg, an ciclopirox would be considered a medium clearance drugwith extraction ration of 0.6 The oral pharmacokinetics are shown inTable 6 below.

TABLE 6 Ciclopirox Pharmacokinetics (30 mg/kg Oral) CPX Prodrug CPXOlamine PK Parameter 30 mg/kg 30 mg/kg Cmax (ng/mL) 520.3 547.8 Tmax(min) 15 15 Beta rate constant (min−1) 0.01316 0.00916 Beta Half-life(min) 52.76 75.67 AUC (ng/mL/kg) 32157.91 57389.8 CL/F (mL/min/kg)722.06 404.602

The IV bolus and oral administration of ciclopirox-POM prodrug andciclopirox olamine were also studied with regard to bioavailability ofciclopirox. The data is shown in Table 7. The IV bolus and oraladministrations are described above.

TABLE 7 Bioavailability of Ciclopirox (IV Bolus v. Oral) IV Oral PKParameter Administration Administration CPX AUC (ng/mL/kg) Prodrug160330.3 32157.91 Olamine Salt 140312.6 57389.8 Foral Prodrug 0.066858Olamine Salt 0.136338 CPX Bioavailability 1.142665 0.560342 FollowingProdrug Administration

The data in the foregoing tables indicates that ciclopirox-POM prodrugas described herein can be an improvement for administration tosubjects. Based on intravenous pharmacokinetics following administrationof ciclopirox olamine, ciclopirox is considered a medium clearance drugbased on intravenous clearance compared to hepatic blood flow in themouse. It was found that ciclopirox was completely bioavailable whengiven IV as the prodrug, compared to IV administration of ciclopiroxolamine, and thereby the ciclopirox-POM is an improvement in chemicalformulation. The data shows that ciclopirox was 50% bioavailable, whengiven as orally as the prodrug, compared to CPX Olamine administered asan oral suspension, which shows an improvement in ciclopirox-POMprodrug. Accordingly, ciclopirox is readily bioavailable when given IVas the prodrug. Based on the inability to detect the prodrug in plasmafollowing IV and oral administration, it appears the prodrug is rapidlymetabolized to ciclopirox when it reaches the systemic circulation.Thus, ciclopirox-POM prodrug has advantages over ciclopirox olamine,from a physicochemical properties standpoint, and can be formulated intoa suitable IV product. Based on the data, it is reasonable to believethat the ciclopirox-POM prodrug is rapidly converted back to ciclopirox.

The term “alkyl” or “aliphatic” as used herein refers to a branched orunbranched saturated hydrocarbon group typically although notnecessarily containing 1 to about 24 carbon atoms, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl,and the like, as well as cycloalkyl groups such as cyclopentyl,cyclohexyl, and the like. Generally, although again not necessarily,alkyl groups herein contain 1 to about 18 carbon atoms, or 1 to about 12carbon atoms. The term “lower alkyl” intends an alkyl group of 1 to 6carbon atoms. Substituents identified as “C₁-C₆ alkyl” or “lower alkyl”contains 1 to 3 carbon atoms, and such substituents contain 1 or 2carbon atoms (i.e., methyl and ethyl). “Substituted alkyl” refers toalkyl substituted with one or more substituent groups, and the terms“heteroatom-containing alkyl” and “heteroalkyl” refer to alkyl in whichat least one carbon atom is replaced with a heteroatom, as described infurther detail infra. If not otherwise indicated, the terms “alkyl” and“lower alkyl” include linear, branched, cyclic, unsubstituted,substituted, and/or heteroatom-containing alkyl or lower alkyl,respectively.

The terms “alkenyl” as used herein refers to a linear, branched orcyclic hydrocarbon group of 2 to about 24 carbon atoms containing atleast one double bond, such as ethenyl, n-propenyl, isopropenyl,n-butenyl, isobutenyl, octenyl, decenyl, tetradecenyl, hexadecenyl,eicosenyl, tetracosenyl, and the like. Generally, although again notnecessarily, alkenyl groups herein contain 2 to about 18 carbon atoms,or 2 to 12 carbon atoms. The term “lower alkenyl” intends an alkenylgroup of 2 to 6 carbon atoms, and the specific term “cycloalkenyl”intends a cyclic alkenyl group, or having 5 to 8 carbon atoms.

The term “substituted alkenyl” refers to alkenyl substituted with one ormore substituent groups, and the terms “heteroatom-containing alkenyl”and “heteroalkenyl” refer to alkenyl in which at least one carbon atomis replaced with a heteroatom. If not otherwise indicated, the terms“alkenyl” and “lower alkenyl” include linear, branched, cyclic,unsubstituted, substituted, and/or heteroatom-containing alkenyl andlower alkenyl, respectively.

The term “alkynyl” as used herein refers to a linear or branchedhydrocarbon group of 2 to 24 carbon atoms containing at least one triplebond, such as ethynyl, n-propynyl, and the like. Generally, althoughagain not necessarily, alkynyl groups herein contain 2 to about 18carbon atoms, or 2 to 12 carbon atoms. The term “lower alkynyl” intendsan alkynyl group of 2 to 6 carbon atoms. The term “substituted alkynyl”refers to alkynyl substituted with one or more substituent groups, andthe terms “heteroatom-containing alkynyl” and “heteroalkynyl” refer toalkynyl in which at least one carbon atom is replaced with a heteroatom.If not otherwise indicated, the terms “alkynyl” and “lower alkynyl”include linear, branched, unsubstituted, substituted, and/orheteroatom-containing alkynyl and lower alkynyl, respectively.

The term “alkoxy” as used herein intends an alkyl group bound through asingle, terminal ether linkage; that is, an “alkoxy” group may berepresented as —O-alkyl where alkyl is as defined above. A “loweralkoxy” group intends an alkoxy group containing 1 to 6 carbon atoms,and includes, for example, methoxy, ethoxy, n-propoxy, isopropoxy,t-butyloxy, etc. Substituents identified as “C₁-C₆ alkoxy” or “loweralkoxy” herein contain 1 to 3 carbon atoms, and such substituentscontain 1 or 2 carbon atoms (i.e., methoxy and ethoxy).

The term “aryl” as used herein, and unless otherwise specified, refersto an aromatic substituent containing a single aromatic ring or multiplearomatic rings that are fused together, directly linked, or indirectlylinked (such that the different aromatic rings are bound to a commongroup such as a methylene or ethylene moiety). Examples of aryl groupscontain 5 to 20 carbon atoms, and aryl groups contain 5 to 14 carbonatoms. Exemplary aryl groups contain one aromatic ring or two fused orlinked aromatic rings, e.g., phenyl, naphthyl, biphenyl, diphenylether,diphenylamine, benzophenone, and the like. “Substituted aryl” refers toan aryl moiety substituted with one or more substituent groups, and theterms “heteroatom-containing aryl” and “heteroaryl” refer to arylsubstituent, in which at least one carbon atom is replaced with aheteroatom, as will be described in further detail infra. If nototherwise indicated, the term “aryl” includes unsubstituted,substituted, and/or heteroatom-containing aromatic substituents.

The term “aryloxy” as used herein refers to an aryl group bound througha single, terminal ether linkage, wherein “aryl” is as defined above. An“aryloxy” group may be represented as —O-aryl where aryl is as definedabove. Examples of aryloxy groups contain 5 to 20 carbon atoms, andaryloxy groups contain 5 to 14 carbon atoms. Examples of aryloxy groupsinclude, without limitation, phenoxy, o-halo-phenoxy, m-halo-phenoxy,p-halo-phenoxy, o-methoxy-phenoxy, m-methoxy-phenoxy, p-methoxy-phenoxy,2,4-dimethoxy-phenoxy, 3,4,5-trimethoxy-phenoxy, and the like.

The term “alkaryl” refers to an aryl group with an alkyl substituent,and the term “aralkyl” refers to an alkyl group with an arylsubstituent, wherein “aryl” and “alkyl” are as defined above. Examplesof aralkyl groups contain 6 to 24 carbon atoms, and aralkyl groupscontain 6 to 16 carbon atoms. Examples of aralkyl groups include,without limitation, benzyl, 2-phenyl-ethyl, 3-phenyl-propyl,4-phenyl-butyl, 5-phenyl-pentyl, 4-phenylcyclohexyl, 4-benzylcyclohexyl,4-phenylcyclohexylmethyl, 4-benzylcyclohexylmethyl, and the like.Alkaryl groups include, for example, p-methylphenyl, 2,4-dimethylphenyl,p-cyclohexylphenyl, 2,7-dimethyinaphthyl, 7-cyclooctylnaphthyl,3-ethyl-cyclopenta-1,4-diene, and the like.

The term “cyclic” refers to alicyclic or aromatic substituents that mayor may not be substituted and/or heteroatom containing, and that may bemonocyclic, bicyclic, or polycyclic.

The terms “halo” and “halogen” are used in the conventional sense torefer to a chloro, bromo, and fluoro or iodo substituent.

The term “heteroatom-containing” as in a “heteroatom-containing alkylgroup” (also termed a “heteroalkyl” group) or a “heteroatom-containingaryl group” (also termed a “heteroaryl” group) refers to a molecule,linkage or substituent in which one or more carbon atoms are replacedwith an atom other than carbon, e.g., nitrogen, oxygen, sulfur,phosphorus or silicon, typically nitrogen, oxygen or sulfur. Similarly,the term “heteroalkyl” refers to an alkyl substituent that isheteroatom-containing, the term “heterocyclic” refers to a cyclicsubstituent that is heteroatom-containing, the terms “heteroaryl” andheteroaromatic” respectively refer to “aryl” and “aromatic” substituentsthat are heteroatom-containing, and the like. Examples of heteroalkylgroups include alkoxyaryl, alkylsulfanyl-substituted alkyl, N-alkylatedamino alkyl, and the like. Examples of heteroaryl substituents includepyrrolyl, pyrrolidinyl, pyridinyl, quinolinyl, indolyl, pyrimidinyl,imidazolyl, 1,2,4-triazolyl, tetrazolyl, etc., and examples ofheteroatom-containing alicyclic groups are pyrrolidino, morpholino,piperazino, piperidino, etc.

The term “hydrocarbyl” refers to univalent hydrocarbyl radicalscontaining 1 to about 30 carbon atoms, or 1 to about 24 carbon atoms, or1 to about 18 carbon atoms, or about 1 to 12 carbon atoms, includinglinear, branched, cyclic, saturated, and unsaturated species, such asalkyl groups, alkenyl groups, aryl groups, and the like. “Substitutedhydrocarbyl” refers to hydrocarbyl substituted with one or moresubstituent groups, and the term “heteroatom-containing hydrocarbyl”refers to hydrocarbyl in which at least one carbon atom is replaced witha heteroatom. Unless otherwise indicated, the term “hydrocarbyl” is tobe interpreted as including substituted and/or heteroatom-containinghydrocarbyl moieties.

By “substituted” as in “substituted alkyl,” “substituted aryl,” and thelike, as alluded to in some of the aforementioned definitions, is meantthat in the alkyl, aryl, or other moiety, at least one hydrogen atombound to a carbon (or other) atom is replaced with one or morenon-hydrogen substituents.

In addition, the aforementioned functional groups may, if a particulargroup permits, be further substituted with one or more additionalfunctional groups or with one or more hydrocarbyl moieties such as thosespecifically enumerated above. Analogously, the above-mentionedhydrocarbyl moieties may be further substituted with one or morefunctional groups or additional hydrocarbyl moieties such as thosespecifically enumerated.

When the term “substituted” appears prior to a list of possiblesubstituted groups, it is intended that the term apply to every memberof that group. For example, the phrase “substituted alkyl, alkenyl, andaryl” is to be interpreted as “substituted alkyl, substituted alkenyl,and substituted aryl.” Analogously, when the term“heteroatom-containing” appears prior to a list of possibleheteroatom-containing groups, it is intended that the term apply toevery member of that group. For example, the phrase“heteroatom-containing alkyl, alkenyl, and aryl” is to be interpreted as“heteroatom-containing alkyl, heteroatom-containing alkenyl, andheteroatom-containing aryl.”

One skilled in the art will appreciate that, for this and otherprocesses and methods disclosed herein, the functions performed in theprocesses and methods may be implemented in differing order.Furthermore, the outlined steps and operations are only provided asexamples, and some of the steps and operations may be optional, combinedinto fewer steps and operations, or expanded into additional steps andoperations without detracting from the essence of the disclosedembodiments.

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its spirit and scope, as will be apparentto those skilled in the art. Functionally equivalent methods andapparatuses within the scope of the disclosure, in addition to thoseenumerated herein, will be apparent to those skilled in the art from theforegoing descriptions. Such modifications and variations are intendedto fall within the scope of the appended claims. The present disclosureis to be limited only by the terms of the appended claims, along withthe full scope of equivalents to which such claims are entitled. It isto be understood that this disclosure is not limited to particularmethods, reagents, compounds compositions or biological systems, whichcan, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodimentsonly, and is not intended to be limiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations. In addition, even if a specificnumber of an introduced claim recitation is explicitly recited, thoseskilled in the art will recognize that such recitation should beinterpreted to mean at least the recited number (e.g., the barerecitation of “two recitations,” without other modifiers, means at leasttwo recitations, or two or more recitations). Furthermore, in thoseinstances where a convention analogous to “at least one of A, B, and C,etc.” is used, in general such a construction is intended in the senseone having skill in the art would understand the convention (e.g., “asystem having at least one of A, B, and C” would include but not belimited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, and/or A, B, and Ctogether, etc.). In those instances where a convention analogous to “atleast one of A, B, or C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, or C” wouldinclude but not be limited to systems that have A alone, B alone, Calone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). It will be further understood by those withinthe art that virtually any disjunctive word and/or phrase presenting twoor more alternative terms, whether in the description, claims, ordrawings, should be understood to contemplate the possibilities ofincluding one of the terms, either of the terms, or both terms. Forexample, the phrase “A or B” will be understood to include thepossibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” and the like include the number recited andrefer to ranges which can be subsequently broken down into subranges asdiscussed above. Finally, as will be understood by one skilled in theart, a range includes each individual member. Thus, for example, a grouphaving 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, agroup having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells,and so forth.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims. All references recited or in the incorporatedreferences herein are incorporated herein by specific reference in theirentirety.

1. A method of forming an active compound in a subject, the methodcomprising: providing a composition having a prodrug compoundrepresented by a structure of Formula 1 or stereoisomer thereof orpharmaceutically acceptable salt thereof; and administering thecomposition to a subject such that the prodrug compound has aphosphoryloxyalkyl prodrug moiety removed therefrom to form the activecompound and a phosphoryloxyalkyl compound in the subject,

wherein: R¹-R¹² each independently include one or more of hydrogen,halogens, hydroxyls, alkoxys, straight aliphatics, branched aliphatics,cyclic aliphatics, substituted aliphatics, unsubstituted aliphatics,saturated aliphatics, unsaturated aliphatics, aromatics, polyaromatics,substituted aromatics, hetero-aromatics, amines, primary amines,secondary amines, tertiary amines, aliphatic amines, carbonyls,carboxyls, amides, esters, amino acids, peptides, polypeptides,substituted or unsubstituted, or combinations thereof; R¹³-R¹⁴ eachindependently include one or more of a positive ion, sodium ion,potassium ion, hydrogen, halogens, hydroxyls, alkoxys, straightaliphatics, branched aliphatics, cyclic aliphatics, substitutedaliphatics, unsubstituted aliphatics, saturated aliphatics, unsaturatedaliphatics, aromatics, polyaromatics, substituted aromatics,hetero-aromatics, amines, primary amines, secondary amines, tertiaryamines, aliphatic amines, carbonyls, carboxyls, amides, esters, aminoacids, peptides, polypeptides, substituted or unsubstituted, orcombinations thereof; n is 1-20 substituted or unsubstituted; and m is0, 1 or
 2. 2. The method of claim 1, the prodrug compound is representedby a structure of Formula 2 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


3. The method of claim 1, the prodrug compound is represented by astructure of Formula 3 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


4. The method of claim 1, the prodrug compound is represented by astructure of Formula 4 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


5. The method of claim 1, the prodrug compound is represented by astructure of Formula 5 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


6. The method of claim 1, the prodrug compound is represented by astructure of Formula 6 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


7. The method of claim 1, the prodrug compound is represented by astructure of Formula 7 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


8. The method of claim 1, the prodrug compound is represented by astructure of Formula 8 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


9. The method of claim 1, the prodrug compound is represented by astructure of Formula 9 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof


10. The method of claim 1, the prodrug compound is represented by astructure of Formula 10 or stereoisomer thereof or pharmaceuticallyacceptable salt thereof.


11. The method of claim 1, wherein the pharmaceutical compositioncomprises the compound and a pharmaceutically acceptable carrier. 12.The method of claim 1, wherein the composition is administered amount toprovide 6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one as thecompound.
 13. The method of claim 1, wherein the phosphoryloxyalkylcompound has a structure of Formula 11:

wherein: R¹⁵ includes one or more of hydrogen, halogen, hydroxyls,alkoxys, straight aliphatics, branched aliphatics, cyclic aliphatics,substituted aliphatics, unsubstituted aliphatics, saturated aliphatics,unsaturated aliphatics, amines, primary amines, secondary amines,tertiary amines, aliphatic amines, carbonyls, carboxyls, amides, esters,amino acids, peptides, polypeptides, substituted or unsubstituted, orcombinations thereof.
 14. The method of claim 13, wherein thephosphoryloxyalkyl compound has a structure of Formula 11A:


15. The method of claim 13, wherein the phosphoryloxyalkyl compound hasa structure of Formula 11B:


16. The method of claim 1, wherein the active compound has a structureof Formula 12:


17. The method of claim 1, wherein the phosphoryloxyalkyl prodrug moietyis enzymatically cleaved from the prodrug compound so as to form thecompound.
 18. The method of claim 1, wherein the compound is formed inan amount sufficient for disrupting DNA repair in a cell in the subject.19. The method of claim 1, wherein the compound is formed in an amountsufficient for disrupting cell division in the subject.
 20. The methodof claim 1, wherein the compound is formed in an amount sufficient fordisrupting intranuclear transport in a cell in the subject.